McGoldrick, in cooperation with the Mayor’s Office, amended the proposal Wednesday during the Board of Supervisors Budget and Finance Committee meeting to require that if the Ethics Commission finds there are insufficient funds for the 2011 mayoral race, The City will sink $5 million into the fund.

"We’re all supportive of public financing. You can put your trust in the fact that that money will be there," McGoldrick said.

However, Supervisor Ross Mirkarimi, who proposed public financing for mayoral races, noted that "Oakland endured a similar desire and motivation to usurp public funds … but those funds were not replenished."

Newsom’s budget proposal used the $5 million to help close a projected $338 million deficit. The Board of Supervisors is scheduled to vote on the $6.5 billion budget July 22.

Advocates of public campaign financing were worried the money would not be there for candidates in future years.

"You are setting a precedent of making this a slush fund to fund your favorite projects," said Steven Hill, director of political reform at the nonprofit New America Foundation.

Voters adopted The City’s first public campaign finance program for candidates for the Board of Supervisors in November 2000. The board’s budget committee will vote next week whether to send the proposal to the full Board of Supervisors.